Derek,

I have not worked with Iron ore slurry system. However, I have been involved in research & system designing of coal-ash slurry disposal system. One of my research paper regarding the selection of safe transport velocity of high concentration ash slurry is scheduled to get published soon in Bulk Solids Handling, Trans Tech Publ., which may provide you some guideline. I suspect that the methodogy for selection of minimium transportation velocity for ash slurry & iron ore slurry should be identical in some respects. However, for any further clarification, please feel free to ask me.

Kind Regrads,

S.S.Mallick ■

Dear Derek

I have laboratory experience with multisized particulate iron ore slurry flowing in pipelines of 2 and 4 inch diameters at concentrations in the range from 10% to 50% by weight. I observed the minimum flow velocity at which particles just started settling at the bottom of pipeline (generally termed as deposition velocity) in the range from 1.7 to 2.4 m/s .

Deposition velocity strongly depends on settling velocity of particles. But in my knowledge, there is no studies available in which deposition velocity is directly correlated with the settling velocity for multisized particulate slurry flow at higher concentrations. The reason behind such uncertainity is the nonavailability of any expression for upward flux due to turbulent diffusion which helps particles to be in suspension for such a slurry flow. However, one can easily predict the deposition velocity for flow of dilute suspensions comprising of equisized particles using Durand [1952] equation.

Kind regards

D.R. Kaushal ■

I observed deposition velocity using following methods:

1. By providing a small length of perspex pipe (obsrvation chamber) in the closed-loop pipeline used in the experiments: The motion of the particles was observed at the bottom of pipeline. Deposition velocity is the flow velocity at which particles just start depositing at the bottom of the observation chamber. This method can be obviously used for any concentration of solids and require transperent test section.

2. Using gamma ray density guage with traversing mechanism: gamma ray density guage was fixed on the traversing mechanism so as to give density just at the bottom of the pipeline. With reducing flow velocity, density at the bottom first increases and then becomes constant due to deposition of particles at pipe bottom. The flow velocity at which the density at pipe bottom just start attaining a constant velocity was taken as deposition velocity. This method can be used for any concentration of solids and do not require transparent test section as gamma ray can pass through pipe metal.

3. Using LDV (Laser Doppler Velocimeter) with traversing mechanism: The particle velocity at the pipe bottom was measured using LDV. The deposition velocity is the flow velocity corresponding to the zero particle velocity at pipe bottom. However, this technique can be used for dilute suspensions (Cv<3%) and requires transparent test section due to the use of laser rays.

Regards

D.R. Kaushal ■

Thanks for sharing your practical experience in large diameter slurry pipelines. I had similar experience with Durand's equation for my experimental data. The overprediction of deposition velocity by Durand's equation for heterogeneous particle sizing may be attributed to the presence of finer particles, which helps greatly keeping the coarser ones in suspension. My experience with multisized particulate slurries alongwith some earlier studies suggest that the flow velocity reaches to deposition velocity for a particular ratio of concentration at pipe bottom and static settled concentration . Static settled concentration is a function of PSD, particle shape and particle density and can be determined easily in laboratory. Concentration at pipe bottom can be determined by my model with reasonable accuracy. Scaling up of experimental data can further check the validity of predicted values or vice versa.

Regards

D.R. Kaushal ■

Originally Posted by soumyasuddha

Derek,

I have not worked with Iron ore slurry system. However, I have been involved in research & system designing of coal-ash slurry disposal system. One of my research paper regarding the selection of safe transport velocity of high concentration ash slurry is scheduled to get published soon in Bulk Solids Handling, Trans Tech Publ., which may provide you some guideline. I suspect that the methodogy for selection of minimium transportation velocity for ash slurry & iron ore slurry should be identical in some respects. However, for any further clarification, please feel free to ask me.

Kind Regrads,

S.S.Mallick

Dear sir

We pleasure to have your interaction. Apparantly you stated about safe transport velocity of high concentration ash slurry . Can you forward the joiurnal at below mail ID

2) Secondly i want to persue MTECH in hydraulic design of coal ash slurry system , how do i takeup this matter ■

hallo

It is few years agou we solve the hydaulic transport in iron mine in russia.

You must address the following issues:

Steel pipe you can shag (water-stone i do not know right name), Chemical reaction in water

you have a different dimension and density of grains.

there is always sedimentation on the bottom line. In the shuffle of the pipeline, creating something like a cork, which also flows through a pipe.

We have 15 km long pipe line we use renteg to see how it flow inside

Result: these cork created equal in the wave of the transported material, which are carried by water.

And therefore it is necessary before switching off the pumps and pipes have flushed out at regular intervals the drain site.

practice-tested speed is 2.2 m / s.

Otherwise, we worked very pipe lined with basalt lifespan is 30 years old and also because the basalt has a smooth surface like glass so it is no longer sticky.

Kohout ■